When the heartburn went down a week ago, I said that I thought that this was much ado about nothing but that it should be a (fixable) wake-up call for Facebook that they need to better establish a better bond with their community.

Clinton, en route to Asia for a key regional summit, stressed following a meeting with her Japanese counterpart in Hawaii that recent Chinese restrictions on sales of the important commercial inputs must serve as a "wake-up call" for the U.S. and its allies to diversify their sourcing.

But Mr. Dongarra and other researchers said the machine should nevertheless serve as a wake-up call that China is threatening to take the lead in scientific computing — akin to a machine from Japan that took the No. 1 position early in the past decade and triggered increased U.S. investment in the field.